The invention relates to an apparatus for feeding a label into a mold cavity of a bottom tool which can be moved up and down in a molding device for thermoforming plastic containers from a plastic film.
In a known apparatus of this kind, a tangential slot is provided within reach of the mold cavity for the introduction of the label previously cut to length from the label strip, and the transport means include a rotatable winding mandrel disposed in alignment with the mold cavity, which during the molding process forms with its end face the bottom of the mold cavity, and toward which the molding device is displaceable in the longitudinal axis of the mold cavity until the winding surface of the winding mandrel lies completely within the mold cavity. The individual label is first wound onto the winding mandrel and, after its introduction into the mold cavity, is unwound from the winding mandrel by rotating the latter in the opposite direction, so as to apply itself to the lateral wall of the mold cavity. When the plastic film is shaped by the thermoforming process with the input of heat, the label is then sealed or adhered to the outer wall of the thermoformed plastic container.
In this known configuration of a label feeding apparatus the molding device is complicated in its construction and troublesome due to the providing of the tangential label introduction slot on the mold cavities. This is contributed to also by the multiple successive movements including the rotatory movement of the winding mandrel in opposite directions to the label insertion, which also greatly retard the process of putting the label into the mold cavity, and also inaccuracies are introduced in the placement of the label on the lateral wall of the mold cavity in the label insertion process.